class Fish{
	 int weight;
	}
class Lake{
	 	Fish fish;
	 	void setFish(Fish s){
		 fish = s;
	 }
	 void eat(int n){
		 fish.weight = fish.weight + n;
	 }
}
class FishandLake{
	public static void main(String[] args) {
		Fish niqiu = new Fish();
		System.out.println(niqiu.weight);
		Lake taihu  = new Lake();
		taihu.setFish(niqiu);
		taihu.eat(15);
		Lake xihu = new Lake();
		xihu.setFish(niqiu);
		xihu.eat(10);
		Lake dongtinghu = new Lake();
		dongtinghu.setFish(niqiu);
		dongtinghu.eat(5);
		System.out.println(niqiu.weight);
		System.out.println(taihu.fish.weight);
		System.out.println(xihu.fish.weight);
		System.out.println(dongtinghu.fish.weight);
	 }
}


